My F27 chassis has plates welded into the chassis. (3-4mm thick)

The plan is to drill a suitable hole in the plate, and then either weld a nut to the top, or pass the bolt through and secure with a nut and washer on the underside.

Which of these routes is best, and are they strong enough, or should I sort the lower harness mounts in another way?







Thanks as always.

Matt

I've got the same but vertically running as oppose to the horizontal you have and they're on the tunnel. I welded a nut to the plate and then ran a piece of square section along the long edge of the plate so that it was enclosed on all sides. There was no issue at SVA. I just showed the examiner photo's and that was it.

cool - so probably ok then running horizontally with a nut welded in the top?

hmm, i'd have a nut underneath. that way the whole strength of the plate is used, rather than just the weld (which if done right i guess should be just as strong)
nut underneath will be easier anyway. i'm going to use those FIA spreader plates under mine, even though i've already got 5mm steel strip welded in

Mine are mounted on the inner edge of the horizontal outer rail and the angled, rising outer rail - effectively the same on the trans tunnel.
Plate is tapped and I've added a lock-nut between the plate and the outer skin (couldn't weld it as it was already assembled when I bought it).
For preference I'd say a plain hole through the plate and weld a full size nut on the opposite side to the belt (not on the same side of the plate as the belt mount) but add a spacer (or top-hat fixing) between belt and mount to allow swivel if the seat adjusts back and forward.
BTW I recently bought a replacement harness from Securon which has pull-up lap straps - sooo much easier to adjust.
HTH.
Cheers, Pewe